Top left, Omega Lock from Cybertron Primus
Middle, small purple missile is from G1 Blitzwing
Two red guns below it go with RiD Rotor
The three jointed hoses below that are for G1 Hot Spot (two of the harder to find parts for him IIRC)
Green gun is for G2 Sideswipe
Two yellow guns are for G1 Nosecone
The two guns at the bottom are for one of RiD Rotor's other releases, possibly the urban camo version.
The little ball thing is a Minicon, it's Armada Dead End ho comes with Unicron.

Second picture:

White fists go with G1 Superion
Small green missile at the top belongs to either one of the Predator Jets, Stalker, Skyquake or possibly Machine Wars Starscream. They all used the same missiles.
The bluish gun below that goes with the redeco of Rotor I mentioned above.
The green bit next to it is a piece from G2 Megatron.
The blue launcher above that goes with G2 Jazz
Silver missile in the middle goes with either G1 Inferno or G1 Grapple. IIRC both had missiles like that.
Next to it is a landing gear for Starscream or one of the other original jets. It's a piece common to all six jet variants and their reuses.
Carrying on down. The two wheels on the black bit of plastic are an arm from Bumblebee or Cliffjumper, or one of their variants.
The gray missile with the arm belongs to G1 Starscream
The red gun with the missile and the arm belongs to G1 Red Alert.
The gray tail fin next to the arm is part of G1 Starscream again.
The yellow missile below the red gun is from one of the Turbomasters - again they all used the same missiles.
Red missile goes with Red Alert again.
The long black missile to the left of those is another bit off of G2 Megatron.
Bright green gun below the missile is from one of the Constructicons.
Back to the middle of the image, you've got another Decepticon jet landing gear.
The gun immediately below it I don't recognise. I want to say it's one of the ones from G1 Metroplex though.
The two guns below that I do know. G2 Megatron's gun is on the right, and a G1 Swindle / RiD Rollbar gun is on the right (they were more or less identical)
The very big missile launcher, IIRC, belongs to the reissue Powermaster Optimus Prime with Apex Armor.
Those three yellow missiles are more parts from Armada Unicron.
There's another G2 Megatron missile below that, and the blue ones go with the green launcher - they're G2 Jazz's missiles.
That gray missile to the left is a part of G1 Starscream.
In the bottom left corner, the L shaped dark green guns are parts for G1 Blast Off. I think that's his gun directly below them.

Third picture:

I'll just cover here what's not covered in the second picture.

Those black bits at the top are the gun stands for the Generation 1 Seacons.
The blue chip thing below them with the Autobot symbol on it is Cybertron Optimus Prime's Cyber Key from the first US release.
The white gun next to it is from Generation 1 Blades.
The black part nearby is a piece of G1 Tracks.
Next to the gray tailfin, there is the chestpiece for Generation 1 Onslaught, or possibly RiD Mega Octane.
The red gun nearby is from RiD Rotor.
To its right, you have two launchers for Generation 1 Thrust, and a launcer for Generation 2 Starscream.
The big purple fists and the large purple gun with them are parts of Generation 1 Devastator (or maybe his Generation 2 release, although the shade of purple looks more like the original.
To their left, you have another landing gear. The gun above it, with the little scope, is another part from G1 Swindle / RiD Rollbar.
The missile below the landing gear is another Decepticon jet's missile, probably one of Thundercracker's.
The gun underneath that is the engine block / gun from Alternators Optimus Prime.
White gun next to that is Generation 1 Blades again.
The white gun with the yellowing is from either Generation 1 or possibly Generation 2 Sideswipe (they had the same gun)
The white missile below is from Generation 1 Tracks.

Our own Resources section has some pretty extensive shots of accessories, especially on Generation 1, if you need to look into this any further.

I can see the longish white missiles are from RID Ultra Magnus. (directly under swindle/rollbar's gun).

That gold rocket above red alerts gun to me looks like it might be from Dinobot Sludge.

I wish I had a few or even just one of those Predator green Rockets my Stalker is short one. and Boss is short a yellow Turbotmaster rocket.

I don't see many bits anymore though - I dread to think that people throw them out thinking no one would want bits - but then that's what Rock Lord & Battle Beast guns are valuable I guess. - to easily misplaced.